Lecture 6 Flashcards
formula for alcohol
CH3-CH2-OH
ethanol is a _____ alcohol
primary
does alcohol have lower or higher boiling point than water
lower
true or false
ethanol can penetrate the placenta but not the brain
false - can penetrate both
true or false
ethanol is both water and lipid soluble
TRUE
allows it to be absorbed easily
_____% of alcohol in the blood is metabolized in the liver
90%
other 10% is through lungs and urine
how long does it take the liver to metabolize 1 unit of alcohol
explain what this means
1 hour
thus, if alcohol is consumed faster than the liver can break it down, the blood alcohol concentration will rise
where is ADH vs ALDH located
ADH - cytosol (alcohol dehydrogenase)
ALDH - mitochondria (aldehyde dehydrogenase)
what is the main toxic part of alcohol
acetaldehyde
final product of alcohol metabolism
acetate
CH3CHOOH
what happens to the acetate from alcohol metabolism
it gets converted to acetyl coA and enters the krebs cycle!!!
this produces energy!!
acetate (the product of alcohol) is converted to acetyl co A which enters the krebs cycle to produce energy
name the specific amount of energy
1 gram of ethanol produces 7 kcal of energy**
_-g of ethanol per day would provide sufficient energy for basic metabolic needs
240g
what cofactor is involved with both steps if alcohol metabolism
NAD reduced to NADH in both steps
what gene is inactive in 50% of asians (related to alcohol metabolism)
ALDH (aldehyde dehydrogenase)
BAC meaning
blood alcohol concentration
the alcohol-induced US death rate is greater than….
100,000
at HIGH DOSES, ethanol is considered a…
CNS depressant
3 mechanisms of alcohol toxicity
- affects the cell membrane
- increases ROS causing injury
- forms conjugates with fatty acids in organs like the heart brain and liver, which alters the membranes bc of high lipophilcity
how does alcohol vs acetaldehyde produce toxicity
alcohol - increases LPS in the gut causing inflammation
acetaldehyde - decreases GSH causing oxidative stress
CNS depressant affects neurotransmitters in the brain
dopamine concentration is _____
serotonin neurotransmission is _____
dopamine concentration is increased
serotonin neurotransmission is decreased
CNS depressants ___ glutamate receptor function
inhibit
CNS depressants _______ GABA receptor function
POTENTIATE
CNS depressants _______ opiate neuropeptide release
stimulate
alcohol decreases serotonin neurotransmission
what does this mean
it is supposed to regulate behavior - thus increases impulsivity and aggressiveness
___ and ____ are natural neural peptides that bind opiate receptors and produce euphoric effects
endorphins and enkephalins
at very high doses, what ais a major concern of alcohol toxicitiy
decrease myocardial contractility, resp depression and coma
ethanol levels above ____% can cause death from respiratory paralysis
0.45%
death usually occurs from ethanol if the concentration in the bloodstream exceeds ____
5%
____ is an opioid receptor antagonist
naltrexone
also nalmefefe
define tolerance
a higher dose is required to produce the same effect
functional tolerance - bc of changes in GABA receptors
withdrawal vs dependence
withdrawal - behaviors like sleep disruption
dependence - compulsive desire to avoid withdrawal
explain the metabolism of METHANOL
metabolized by alcohol dehydrogenase to FORMALDEHYDE and then to FORMIC ACID
both cause toxicity (formic acid is more)
antidote for methanol toxicity
fomepizole
an ethanol and ADH inhibitor
which has a higher affinity for ADH (alcohol dehydrogenase) — ethanol or methanol?
ethanol has 10-20x higher affinity
explain metabolism of isopropanol
forms acetone - same toxicity as ethanol, but isopropanol is twice as toxic at the same blood levels
drinking greater than ____ of formaldehyde results in death
30mL
